Abrasive cutting wheels are used for a large number of purposes. Specifically, one may use abrasive cutting wheels for the preparation of samples of small metal objects or the like which are embedded in a plastic mounting. One then cuts through or along the sample in preparation for microstructural analysis of the material of the object, typically before polishing steps. By such procedures, wafers of materials or small metal parts, printed circuit boards, composite materials, and the like may be analyzed as to their microstructure, while the small material samples are conveniently embedded in the plastic mounting.
Conventional apparatus is available for such abrasive wheel cutting. However, in many cases, the operator has had to carefully monitor the cutting process, and, by a manual control, intermittently advance the abrasive wheel into the object to be cut. Such intermittent advancement prevents particles from becoming embedded in the abrasive surface of the wheel, which results in the burnishing and overheating of the article being cut. Such overheating, if not avoided, can spoil the object for its intended purpose, for example, analysis of the normal microstructure of its surface. Additionally, excessive uniform advancement of the abrasive wheel into the object to be cut can actually cause the wheel to deflect due to adhering material, resulting in a deviation from the desired cutting path.
By this invention, improvements in the quality of cutting processes with abrasive cutting wheels can be achieved, without the need for a skilled operator to oversee the process to provide manual intermittent advancement of the wheel into the object to be cut by a manual control, which, is of course, a time consuming matter. Instead, by this invention, an automatic, desired intermittent advancement of the abrasive wheel can be provided to achieve the significant advantages of this invention. By this invention, abrasive wheel life may be extended, and improvements in the quality of the cut surface of the object cut may make it possible to avoid a later rough polishing step which might otherwise be required prior to microstructural analysis of the cut piece.